See full NASA News Feature: Scientists Discover the First Earth-size Rocky Planet:

Excerpt: Kepler-78b whizzes around its host star every 8.5 hours, making it a blazing inferno and not suitable for life as we know it. ..."The news arrived in grand style with the message: 'Kepler-10b has a baby brother,'" said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center in Moffett Field, Calif. Batalha led the team that discovered Kepler-10b, a larger but also rocky planet identified by the Kepler spacecraft. "The message expresses the joy of knowing that Kepler's family of exoplanets is growing," Batalha reflects. "It also speaks of progress. The Doppler teams are attaining higher precision, measuring masses of smaller planets at each turn...."

...Two independent research teams ... used ground-based telescopes to confirm and characterize Kepler-78b. To determine the planet's mass, the teams employed the radial velocity method to measure how much the gravitation tug of an orbiting planet causes its star to wobble. Kepler, on the other hand, determines the size or radius of a planet by the amount of starlight blocked when it passes in front of its host star.

...Kepler-78b is the first to have both a measured mass and size. With both quantities known [1.2 times the size of Earth and 1.7 times more massive], scientists can calculate a density ... that is the same as Earth's ... primarily of rock and iron.

...One team led by Andrew Howard from the University of Hawaii in Honolulu, made follow-up observations using the W. M. Keck Observatory atop Mauna Kea in Hawaii. [other members of Howard’s team are Roberto Sanchis-Ojeda (MIT), who analyzed the transit data taken by the Kepler spacecraft to find the planet and calculate its size, Dr. Geoffrey Marcy (University of California, Berkeley), Dr. John Johnson (Harvard), Dr. Debra Fischer (Yale), Benjamin Fulton and Evan Sinukoff (UHM graduate students), and Dr. Jonathan Fortney (University of California, Santa Cruz).]

The other team led by Francesco Pepe from the University of Geneva, Switzerland, did their ground-base work at the Roque de los Muchachos Observatory on La Palma in the Canary Islands. More information on their research can be found here.

...This result will be one of many discussed next week at the second Kepler science conference Nov. 4-8 at Ames....

Scientists from around the world are gathered this week at NASA's Ames Research Center in Moffett Field, Calif., for the second Kepler Science Conference, where they will discuss the latest findings resulting from the analysis of Kepler Space Telescope data.

Included in these findings is the discovery of 833 new candidate planets, which will be announced today by the Kepler team. Ten of these candidates are less than twice the size of Earth and orbit in their sun's habitable zone, which is defined as the range of distance from a star where the surface temperature of an orbiting planet may be suitable for liquid water.

At this conference two years ago, the Kepler team announced its first confirmed habitable zone planet, Kepler-22b. Since then, four more habitable zone candidates have been confirmed, including two in a single system.

New Kepler data analysis and research also show that most stars in our galaxy have at least one planet. This suggests that the majority of stars in the night sky may be home to planetary systems, perhaps some like our solar system.

"The impact of the Kepler mission results on exoplanet research and stellar astrophysics is illustrated by the attendance of nearly 400 scientists from 30 different countries at the Kepler Science Conference," said William Borucki, Kepler science principal investigator at Ames. "We gather to celebrate and expand our collective success at the opening of a new era of astronomy."

From the first three years of Kepler data, more than 3,500 potential worlds have emerged. Since the last update in January, the number of planet candidates identified by Kepler increased by 29 percent and now totals 3,538. Analysis led by Jason Rowe, research scientist at the SETI Institute in Mountain View, Calif., determined that the largest increase of 78 percent was found in the category of Earth-sized planets, based on observations conducted from May 2009 to March 2012. Rowe's findings support the observed trend that smaller planets are more common.

An independent statistical analysis of nearly all four years of Kepler data suggests that one in five stars like the sun is home to a planet up to twice the size of Earth, orbiting in a temperate environment. A research team led by Erik Petigura, doctoral candidate at University of California, Berkeley, used publicly accessible data from Kepler to derive this result.

Kepler data also fueled another field of astronomy dubbed asteroseismology -- the study of the interior of stars. Scientists examine sound waves generated by the boiling motion beneath the surface of the star. They probe the interior structure of a star just as geologists use seismic waves generated by earthquakes to probe the interior structure of Earth.

"Stars are the building blocks of the galaxy, driving its evolution and providing safe harbors for planets. To study the stars, one truly explores the galaxy and our place within it," said William Chaplin, professor for astrophysics at the University of Birmingham in the United Kingdom. "Kepler has revolutionized asteroseismology by giving us observations of unprecedented quality, duration and continuity for thousands of stars. These are data we could only have dreamt of a few years ago."

Kepler's mission is to determine what percentage of stars like the sun harbor small planets the approximate size and temperature of Earth. For four years, the space telescope simultaneously and continuously monitored the brightness of more than 150,000 stars, recording a measurement every 30 minutes. More than a year of the collected data remains to be fully reviewed and analyzed.

Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Frank Drake gave a very good talk tonight at the Kepler science conference and I listened in at connect.arc.nasa.gov/kepler

Highlights:

- Interesting take on the Fermi paradox: he thinks that ET would find it more efficient to explore interstellar space through radio and telescopes rather than expend lots of energy trying to get craft going up to near light speed. Thus he thinks that there wouldn't be any "alien visitors".

- The window for an alien civilization trying to find us (or us trying to find a given alien civilization) could be short indeed as our technology is getting more efficient and our signals aren't leaking out as much. Other civilizations could follow courses similar to ours.

- Our search should be directed to the galactic bulge as there are more stars there, and F, G, K, M stars should be searched, and that the search should be done now due to the item noted above (getting more "radio silent").

- The habitable zone could be very wide indeed, if you take into account moons like Europa with a subsurface ocean, and even the possibility of microorganisms or "floaters" in the atmospheres of gas giants. For human like forms the habitable zone would of course be more limited.

- Kepler's only able to see planets that cross the face of the star (transits) and the planets that have been seen have been pretty close to the star, as for planets further out the alignment really has to be just right, less probability of seeing transit then. What Kepler's seen is "just the tip of the iceberg".

The conference goes on till Friday, you can also follow on Twitter with the tag #Kepler2. I'm not there or anywhere near the Bay Area but the tag and the web link kinda made me feel like I was there.

Logged

I'll even excitedly look forward to "flags and footprints" and suborbital missions. Just fly...somewhere.

Just curious...are Mars and Venus considered to be in the "habitable zone" of our Sun ??...i know they don't have watertoday but the certainly in the case of Mars it seems that water did appear on the surface at one time....

I'm asking because the number of billion of earth like planets being estimated now might lead people to think every one ofthose planets are real Earth like, water, plants, etc...when point fact how many might be like Mars or Venus...about the same size as Earth, rocky, but quite dead..

Just curious...are Mars and Venus considered to be in the "habitable zone" of our Sun ??...i know they don't have watertoday but the certainly in the case of Mars it seems that water did appear on the surface at one time....

Venus is at the innermost edge at best. It's basically too close to the Sun. Some studies include Mars and even Ceres. That's not to say Ceres would ever be habitual, but an Earth-like planet there could be.

Frank Drake gave a very good talk tonight at the Kepler science conference and I listened in at connect.arc.nasa.gov/kepler

Highlights:

- Interesting take on the Fermi paradox: he thinks that ET would find it more efficient to explore interstellar space through radio and telescopes rather than expend lots of energy trying to get craft going up to near light speed. Thus he thinks that there wouldn't be any "alien visitors".

- The window for an alien civilization trying to find us (or us trying to find a given alien civilization) could be short indeed as our technology is getting more efficient and our signals aren't leaking out as much. Other civilizations could follow courses similar to ours.

There are probably millions (I'm not saying billions) of planets that might be habitable by humans in our galaxy alone. And life, at least as we concieve it, may be abundant on many of them.

Still, that doesn't mean that we may hear from E.T. soon. Life may be plentiful, complex life may even be fairly abundant, but intelligent life may be very rare. And even intelligent life does not mean that a civilization, such as we can concieve it, will arise. Or, even if there is actually an alien civilization, that it would necessarily share our desire to explore the universe.

Unfortunately, we have only one known example of a civilization: Our own. And here, the numbers aren't kind. Consider: There are probably 10 million species on our planet right now. Add to that the fact that more than 99% of all species that ever existed on our planet have already gone extinct; it means that the statistical chance of intelligent life arising may be somewhare around 1:1 billion (I'm leaving a little benefit of doubt here for some of the other highly evolved terrestrial species that may potentially be counted as "intelligent" as well, some of the Big Apes, and possibly cetaceans). But the chance of actually arising is probably closer to 1:10 billion. And that civilization might only be detectable by radio for a few hundred years, before either going extinct or rising above radio or even the desire to explore...

I think Venus is in the uncertainty zone. The closeness to the star depend also on the atmospheric albedo. And please remember that for each star it might be different (different combination of spectrum and energy throughput). Also, the case for moons of gas giants is different and might be expanded further out (I can't find the paper). And we're talking about habitability for humans. Ammonia or methane based forms (if possible at all) have different requirements.

While it's unfortunate that they can't get any more time on the original field, it really sounds like they have a solid plan to do some very interesting science. Of course, they are the ones who have to sell this plan to HQ, so they aren't neutral party...

Lots of other good stuff the rest of the talks too. Aside from many recent Kepler results, the Nov 6 session has detailed descriptions of future exoplanet missions. Having heard the details, I'm a lot more excited about TESS than I was when the selection was announced.

I grabbed a couple of screenshots from Charlie Sobeck's talk detailing the attitude issues. Can somebody explain the second slide and the graphs? Because I sure as hell am confused.

Shouldn't the only thing that determines the solar pressure torque about the boresight, be the angle between the solar/radius vector and the body normal at the "ridge"? Why does the attitude of the spacecraft with respect to the ecliptic matter at all?

In other words, Consider a circular orbit, and the telescope pointing in the -ve velocity direction, with arrays pointed at the sun, and oriented such that the orbital plane itself is a plane of symmetry for the scope, passing through the its "ridge". Now rotate it about the -ve velocity vector (along the boresight) by |20 degrees|.Consider a second situation, where the telescope's pointing normal to the orbital plane, but the arrays still face the sun, and the plane containing the radius vector and the normal to the orbital plane functions as a plane of symmetry for the scope, passing through its "ridge". Now rotate it about the boresight by the same |20 degrees|.

Shouldn't the magnitude of the solar torque about the boresight be exactly the same in both cases?

Note: The scales of the two graphs are different. The first one has Y axis as angle (arcsec) vs time (hours), and the second graph has a Y axis (degrees) vs time (days) [not shown, but mentioned verbally in the talk]. The second one corresponds to a pointing direction along the negative velocity vector (to keep the Earth out of the FOV), in the ecliptic, and the first one's for the original Kepler FOV (out of the ecliptic).

I assume the four different curves are for different roll rates measured about the X axis - at different times in the orbit. (Which I don't get either.)

Assuming a 'normal' attitude (pun intended. i.e. pointing at right angles to the orbital plane, or.. any non-zero angle actually), without solar pressure torque, Kepler wouldn't roll about its boresight, and the attitude would be fixed in inertial space (discounting the adjustments made in the other planes for pointing).

However, as Kepler moves in its orbit, the hemisphere of the scope that's illuminated, rotates about the ridge line. From the NASA illustration in Grondilu's post, this would produce a torque that tends to keep the ridge always facing the sun (i.e. opposing the telescope's rotation, as seen from the sun). While this torque is nowhere near strong enough to keep the same hemisphere of Kepler always facing the sun (a la Light and Dark side of the Moon, as viewed from Earth) - it's still an unbalanced torque (whose magnitude varies in proportion with the angle between body normal at ridge and solar radius vector - as evidenced by the non-linearity of the first graph), and this rotates the telescope ( a no-no for observations).

This still doesn't explain the multiple curves in the second graph though. If the ridge lies in the orbital plane, then, regardless of the hemisphere of the telescope that's illuminated - it's still illuminated symmetrically around the ridge.